Device and method for chambering telescoped caseless ammunition



March 24, 1970 P. J. HENSLEZY E L 3,501,358 DEVICE AND METHOD FOR CHAMBERING TELESCOPE!) CASELESS AMMUNITION 5 Sheets-Sheet 1 Filed Dec. 28, 1967 2l6ll8 22 FIG. 2

PERRY J.HENSLEY JAMES O. MACK JR. INVENTORS.

ATTORNEY March 24, 1970 P, J, ENsL ET AL 3,501,858 DEVICE AND METHOD FOR CHAMBERING TELESGOPED CASELESS AMMUNITION Filed Dec. 28, 1967 5 Sheets-Sheet 2 PERRY J. HENSLEY FIG. 4 JAMES o. MACK JR. INVENTORS.

BY Lmi 15' 1 54.,

ATTORNEY 5 Sheets-Sheet 5 PERRY J HENSLEY JAMES O. MACK, JR. INVENTORS BY WMZ MW ATTORNEY P. J. HENSLEY ET AL March 24, 1970 DEVICE AND METHOD FOR CHAMBERING TELESCOPED CASELESS AMMUNITION Filed D80. 28, 1967 tates te US. Cl. 42-16 10 Claims ABSTRACT OF THE DISCLOSURE A device is provided for chambering the projectile of a telescoped round of caseless ammunition so that substantially forward obturation of the round is accomplished prior to the ignition of the propellant charge.

This invention relates to a device and method for chambering caseless cartridges. More particularly, this invention relates to a chambering device which can be used in a single shot or automatic firearm for chambering a telescoped round of caseless ammunition.

The term telescoped round of caseless ammunition as used herein is defined as a round comprised of a propellant charge having an axial bore throughout, a projectile secured within the axial bore and a primer. The Wall of propellant formed by the axial bore in the propellant charge surrounds the projectile. The projectile has a surface spaced from the primer for receiving the chambering means of this invention whereby no contact is made between the primer and chambering means.

Telescoped caseless ammunition to be fully effective must be chambered in the barrel of the firearm prior to complete ignition of the propellant charge. Failure to chamber the projectile until after the propellant charge is ignited results in loss of gases ahead of the projectile, thereby decreasing the efficiency of the round. A preferred embodiment of a round of caseless ammunition from a firearm designers point of view is a telescoped round that has a cylindrical outside configuration that can be positively chambered, providing forward obturation prior to ignition of the propellant charge. A round with a cylindrical outside configuration is desirable since this is the optimum configuration to handle in mechanical feed systems for rapid fire weapons. Caseless ammunition designed along conventional lines can be readily chambered. This ammunition, however, does not have the compactness or the configuration desired for use with advanced design rapid fire weapons.

Accordingly, it is an object of this invention to provide a device for chambering the projectile of a telescoped round of caseless ammunition prior to ignition of the propellant charge, thereby providing forward obturation for the round.

It is a further object of this invention to provide a method for chambering a telescoped round of caseless ammunition.

Other objects of this invention will, in part, be obvious and will, in part, appear hereinafter. For a complete understanding of the nature and the objects of this invention, reference is made to the following detailed description and drawings.

In accordance with this invention, there is provided a device forming a part of a firearm for chambering the projectile of a telescoped round of caseless ammunition in the barrel of a firearm prior to ignition of the propellant charge. This device is comprised of a bolt having a forward end of a reduced diameter in axial alignment with the bolt, said diameter being smaller than the diameter of the bore of the propellant charge, and of a length sufficient to move the projectile into the barrel of the firearm. The forward end of the bolt has a bolt face which provides a surface for contacting a surface at the base of the projectile spaced from the primer for receiving the bolt face. The bolt face does not contact the primer. A firing pin is centrally disposed within said bolt for initiating the primer of the chambered round.

FIG. 1 is a longitudinal view of the breech end of a bolt-operated firearm showing a bolt having a centrally disposed firing pin, which is employed in chambering and firing a telescoped round of caseless ammunition.

FIG. 2 is a sectional view taken along line A--A of FIG. 1 illustrating the structural details of the bolt.

FIG. 3 is a longitudinal view similar to FIG. 1 wherein the projectile and bolt are both in firing position.

FIG. 4 is a longitudinal view of the breech end of a bolt-operated firearm showing a bolt having multiple firing pins designed to chamber and fire another embodiment of a telescoped round of caseless ammunition.

FIG. 5 is a longitudinal view of a bolt-operated firearm showing means for urging the bolt into the base of the telescoped round illustrated in FIGURE 1.

In FIG. 1, a round of telescoped caseless ammunition having a propellant charge 12 with an axial bore throughout its length, a projectile 14 and a primer 16 is loaded into the breech end of a bolt-operating firearm 18 having a chamber 20 and a barrel 22. The front edges 24 of the propellant charge 12 are positioned against the neck 26 of the chamber of the firearm. The position of the telescoped round heretofore described is referred to as the loaded position.

The projectile 14 is chambered whereby substantially forward obturation is accomplished by action of the forward movement of a reciprocating :bolt 28 having a forward end 30 of reduced diameter in axial alignment therewith. In its forward movement, the forward end 30 of the bolt 28 exerts a force on a surface 32 provided at the base of the projectile spaced from the primer 16 thereby causing the projectile to move into the barrel 22 of the firearm without contacting the primer.

The reciprocating bolt 28 has a central hole 36 therethrough and a longitudinally slidable firing pin 34 with a striker 35 centrally disposed within this central hole 36.

The chamber of the firearm 20 is obturated at the rear 1 by an O-ring 38 which is held in a slot 40 in the periphery of the bolt 28. Other obturation means such as metal seals or a combination of metal seals and O-rings can be employed.

The forward end 30 of the bolt 28 is machined to a reduced diameter, said diameter being smaller than the diameter of the bore of the propellant charge. The forward end 30 of the bolt 28 is bored the entire length of the forward end and ground so as to provide four extension members 42 and a bolt face 44.

As shown in FIG. 2, each of the four extension members 42 has a cross-sectional area similar to a quadrant of a circle that has a central hole, and are spaced an equal distance from each other and from an axis 46 through the center of the forward end of the bolt. The extension members are sized such that four longitudinal openings 48 are formed along the outside of the bolt. These longitudinal openings 48 provide paths for flame from the primer so that a large propellant charge surface area is exposed to primer flame for rapid and complete ignition of the propellant charge, and also to provide area for gas expansion within the chamber.

FIG. 3 illustrates the relative positioning of the projectile 14, propellant charge 12, and bolt 28 when the caseless round is in firing position. The projectile 14 is chambered by action of the forward movement of the bolt 28 driven forward by a suitable means (not shown) and in particular by the forward force applied to a surface 32 at the base of the projectile 14 spaced from the primer by the face 44 of the forward end of the bolt 28. This forward force on the surface 32 provided at the base of the projectile spaced from the primer breaks the adhesive bond or other securing means between the projectile 14 and the propellant charge 12 and the projectile 14 moves into firing position. In this position, the face 44 of the forward end of the bolt is in direct contact with the surface 32 provided at the base of the projectile spaced from the primer. The movement of the forward end of the bolt 28 into the bore of the propellant charge is predetermined by weapon design and is set so that the projectile 14 is moved into firing position whereby forward obturation of the round is substantially accomplished.

When the firing pin 34 is driven forward by suitable means, such as a hammer (not shown), the striker 35 is forced into the primer detonating it. Flames from the detonated primer move along the longitudinal openings provided, igniting the propellant.

FIG. 4 illustrates another embodiment of a chambering device for use with a telescoped round of caseless ammunition. The bolt is prepared from two sections, an aft section and a fore section. The front end of the aft section 54 of the bolt is of a reduced diameter and threaded. The fore section '52 of the bolt 50 is threadably mounted to the front end of the aft section 54 and in axial alignment therewith. The threadably mounted fore section 52 provides a recess 56 between the fore and aft sections of the bolt of sufiicient depth to completely house the firing pin 58 and strikers 60. No portion of the strikers protrudes from the base 62 of the force section 52 of the bolt, when the firing pin is at the rear of recess 56, which is the ready firing position 64 for the firing pin. The base 62 of the fore section 52 has a number of evenly spaced holes 66 on its periphery in alignment with the strikers 60. The foreward end of the fore section 52 of the bolt is comprised of four extension members 68 connected at one end to the base62 of the fore section 52 and connected at the opposite end to the face of the bolt 70. The extension members 68 are sized so as to provide longitudinal openings as paths for flames from an initiated primer. The forward end of the fore section of the bolt 50 is of a diameter less than the diameter of the bore of the propellant charge.

The firing pin having multiple strikers is positioned in a central hole 72 in the bolt. The strikers form an integral part of the firing pin. When the bolt moves forward to chamber the projectile, the firing pin is in ready fire position 64.

After the projectile is chambered, the firing pin 58 with multiple strikers '60 is driven forward by suitable means, such as a hammer (not shown). The strikers are forced into the primer which is held in an annular cavity at the base of the propellant charge, whereupon the primer 74 i is detonated with subsequent ignition of the propellant charge.

In FIGURE 5 bolt 28 is illustrated at its point of forwardmost movement with projectile 14 in firing position. Movement of bolt 28 is controlled by slide 76 which is connected with bolt 28. The bolt and slide are connected through a slotted section. This slotted section straddles magazine 80 and hammer 82. Bolt 28 reciprocates within barrel 22 and receiver 84, and slide 76 reciprocates within slide housing 86 during firing of the weapon. In the firing position slide 76 contacts forward face 88 of housing 86 and is held in this position by return spring 90. To fire the round, a trigger (not shown) releases hammer 82 which drives firing pin 34 forward detonating primer 16. Projectile 14 is fired through barrel 22. Blow back of gases from the burning propellant charge 12 drives bolt 28 and slide 76 rearward compressing return spring 90 and forcing hammer 82 into cocked position. Return spring 90 then functions to force bolt 28 and slide 76 3 forward and can simultaneously feed aonther caseless round (not shown) from magazine 80 into chamber 20 of the Weapon.

From the foregoing description and drawings, it is clear that many modifications can be made in embodiments of a chambering device to chamber telescoped rounds of caseless ammunition without departing from the spirit or scope of the invention described herein. Thus the bolt can be prepared in one section or multiple sections. The forward end of the bolt can have any number of extension members, and the bolt face can be modified as required so as to provide a surface to chamber the projectile of the telescoped round without contacting the primer. The bolt can be moved forward into the bore of the propellant charge by any suitable means. Examples of suitable bolt actions well known in the art which can be employed include manual action, blow-back action, recoil operated action, gas operated action and the like. Operation of bolt actions of this type are described in U.S. Patents 2,975,679; 3,129,637; 3,103,142 and 3,314,183.

What we claim and desire to protect by Letters Patent is:

1. A device for chambering a telescoped round of caseless ammunition comprised of a propellant charge having an axial bore throughout, a projectile fully contained within the axial bore, and a primer, said chambering device forming a part of a firearm having in combination a chamber and a barrel, said chambering device comprising (a) a bolt having a forward end of reduced diameter in axial alignment with the bolt; the forward end of the bolt having a diameter smaller than the bore of the propellant charge, having a face providing surface area for contacting a surface at the base of the projectile, spaced from the primer, for receiving the bolt face, and being of a length sutficient to move the projectile into the barrel of the firearm to substantially forwardly obturate the caseless round,

(b) a means for urging said bolt forward into the bore of the telescoped round whereby the projectile is chambered, and

(c) a firing means centrally disposed within said bolt for detonating the primer whereby the chambered projectile is fired through the barrel of the firearm.

2. The device of claim 1 wherein the forward end of the bolt is comprised of extension members and a bolt face, said extension members sized so as to provide longitudinal openings as paths for flames from an initiated primer.

3. The device of claim 1 wherein the bolt is prepared in two sections, a fore section comprising the forward end of the bolt and an aft section, said fore section threadably mounted to said aft section, said fore section comprised of extension members connected at one end to the base of the fore section and connected at the opposite end to the face of the bolt, said extension members sized so as to provide longitudinal openings as paths for flames from an initiated primer.

4. The device of claim 1 wherein the firing means is comprised of a firing pin and striker centrally disposed Within said bolt.

5. The device of claim 1 wherein the firing means is a firing pin centrally disposed within said bolt having multiple strikers.

6. The device of claim 2 wherein the firing means is comprised of a firing pin and a striker centrally disposed within said bolt.

7. The device of claim 2 wherein the firing means is a firing pin centrally disposed within said bolt having multiple strikers.

8. The device of claim 3 wherein the firing means is comprised of a firing pin and a striker centrally disposed within said bolt.

9. The device of claim 3 wherein the firing means is a firing pin centrally disposed within said bolt having multiple strikers.

10. A method for firing a telescoped round of caseless ammunition having in combination a propellant charge with an axial bore throughout, a projectile fully contained within the axial bore, and a primer, in a bolt-operated firearm having a chamber and a barrel, which method comprises.

(a) loading the telescoped round of ammunition into the chamber of the firearm,

(b) advancing the projectile from its position in the loaded telescoped round prior to chambering of the projectile forward through the axial bore in the propellant charge into the barrel of the firearm without 15 contacting the primer until chambering of the round is accomplished, and (c) firing the round.

References Cited UNITED STATES PATENTS US. Cl. X.R. 

